Speed regulator for automatic guns



Aug. 14, 1945. s. GREEN 1 2,382,411

SPEED REGULATOR FOR AUTOMATIC GUNS Filed Oct. 14, 1940 2 Sheets-Sheet 1 Fig 1 jumua i fg w ee-n. BY Hwy/ ll, $8M

ATTORNEY Aug. 14, 1945. a @REEN 2,382,411

SPEED REGULATOR FOR AUTOMATIC GUNS Filed 001:. 14, 1940 2 Sheets-Sheet 2 IINVENTOR .Snmu E1. E1. E1 E an" BY W avg/[QM ATTORNEY A still f'urtherl obj Patented Aug. 14, 1945 UNITED STATES PATENT. OFFICE v v 2,ss2-,411

. SPEED REGULATOR FOR AUTOMATIC Guns: I Samuel G. Green, Gray, Ga..." I Application October 14, 1940, Serial "No. 361,095 10 Claims. (o1. 42.. s.):'

(Granted under the act ofMarch 3'; 1883, as

amendedApril30. 1928; 3700; G. 757) expansion of the entering gases will be permis The invention described herein may be manufactured and used by or' for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a gas regulator for automatic weapons actuated by gas.

The principal object of this invention is to provide a gas regulator having. a gas chamber ported direct to atmosphere and so proportioned to the port and the displacement of apiston in A communication with the chamber that the ratio of expansion of the gas admitted to the chamber with respect to the piston displacement will be such as to impart a uniformly increasing acceleration to the piston, maintain the temperature of the gas in the chamber sufliciently high for a sufiicient period of time to'efiect combustion of combustible particles passing to the chamber, and be of such volumetric capacity asto receive anexcess of gas so that the volume passing to atmosphere by way of said port will not sufiioiently minimize the efiect of the initial volume received in the chamber as to reduce the pressure below a critical operating pressure.

A further object ofthe invention is to provide a gas regulator which will have a minimum ad'- justment, as to'gas ported to atmosphere from the gas chamber, effect actuation of the weapon in accordance with a predetermined standard when the lowest powered ammunition designed for use with the weapon unto which the regulator is attached is used, and whichis adjustable to a maximum adjustment to increase said porting effect when higher powered ammunition is" used for the purpose of effecting duplication of'sa'id predetermined standard whereby a uniform operating power source is maintained in service irrespective of the type of 'mmumuon used. ect of the invention isto communicating, with an operating piston is ported to atmosphere and is of such'volumerelative to the piston displacement andport that the pressure built up in the chamber will be relatively provide a gas regulator wherein agas chamber gradual thus obviating the shock, or impact iniparted to a weapon where the pressure is built up' instantaneously in a gas chamber by sudden arrestation of expansion ofthelenterlng gases. Another object of the inventionis to so p roportion the volume ,of the gas chamberofa ga regulator that the elasticity of. the gases may b utilized in absorbing shoci'n f 1 Still another object otth invention is to provide a gas chamber in a {gasregulato'r wherein sible over a relatively lon period of time thereby provi ing for, l tion of t ep w rsource over a correspondingly long period with consequent moreuniform application thereof and accompanying increased uniformity of operation of the w pon.

1 Astill further. object of the invention is to provide a gas regulator having a gas chamber provided with an operating piston formed of such material that the piston may breach Carbon or fouling depositions from the. zone of the cylinder in which the piston works, and deposit the broachedmatter in the gas chamber to be ex.-

hausted therefrom byinherent action of the,

regulator. c

A further. objerit of the invention isto form the operating piston he'adwhich cooperates in forming the structural combinationof the gas regulatonof a material harderthan carbon and capable of maintaining a red hardness under heat in the vicinity of 1500 F. so that it may serveas a broach to breach its cooperating, cylinder portion clear of carbon or similar fouling deposits. I 3

A still"v further object of the invention is to provide a gas regulator that will maintain uniformity of the operating cycle of a weapon'unto which it is attached whereby the adaptation of a cyclic rate reducing mechanism may be facilitated.

The specific nature ofthe invention as well as other objects an'd'advanta'ges thereof will clearly appearirom a description of a preferredembodiment as shown'in the accompanying drawings in which:

Fig. 1' is a longitudinal sectional view of a preferre'd'form of-the gas regulator of this invena modified form of throttle valve for use in the regulator of Fig. 1;

Fig. 5 is a longitudinal sectional view showing a modified forniof gas regulator;

Fig. 6 is a view similar to Fig. 5 showing a further modified form ofgas regulator.

Reference is now made to th 'dra ings ei r es o ding elemen s a ident fied y 0 -to be aligned with the port 23.

cupies a position shoulder M as indicated at 15 for interthreaded engagement with complementary threads l6 provided on the interior end portion of the ga cylinder tube ll. Forwardly of the shoulder [4 the gas cylinder tube sleeve I3 is of a greater outside diameter than the rearwardly extending portion bearing the threads I 5 so as to facilitate the provision of an annular valve seat I! extending forwardly and outwardly from the surface defining the bore 18 of the sleeve. "To demountably secure the sleeve I3 in assembled relation with respect to the gas cylinder tube I l a lock washer l9 having a plurality of spaced deformable locking tabs 20 is interposed between the shoulder ll of the "sleeve and adjacent end of the gas cylinder tube l l with provision made, such as the recesses 21 and 22 in the shoulder l4 and gas cylinder tube II, respectively, to have the tabs 20 deformed thereinto for interlocking the sleeve and gas cylinder tube.

Communication between the bores of the barrel In and sleeve I3 is established by means of a gas port 23 provided in the barrel l0, front gas cylinder tube bracket 'IZ gas tube cylinder II and 'a port 24 in the sleeve l3 which is adapted To ensure expeditious assembly of the sleeye l3 with the gas cylinder tube 1! in such manner that the gas ports 23 and 24 will be properly aligned, the topmost locking tab 20of the lock washer I9 is so dimensioned with respect to the remaining tabs '20 that it alone may be deformed into the cor responding topmost recess 22 which is ali ned with the gas port23, and provided with an alignment symbol 25 so disposed as to be visible when the tab is deformed into locking relation with the "gas cylinde'r tube as clearly shown in Fig. 2. A

coacting alignment symbol 26 is suitably inscribed or otherwise formed upon the shoulder M of the sleevel3 whereby when'th'e shoulder is brought into abutting or substantial abutting relation with the lock washer I9 with the alignment'symbols' 25 and 26 inproper alignment the gas ports 23 and 24 as shownin Fig. 1, will be properly aligned. While the topmost tab 20 has been described-as bearing the alignment symbol 25 it is to be understood that such description is to by way of illustration and not of limitation,-as the; tab 20 bearing=symbol 25 may be circumferentially disposed with-respect to the gas cylinder tube H a desired, although in practice the location described and shown in Figs. 1 and 2 is to bepreferred. I 1

A piston 21 is mounted within the gas cylinder tube. II for reciprocable movement and is provided with a piston head generally indicated at 28 which comprises a piston ring or rings 29secured to the body of the piston by the ring securing stud 30 as shown in Fig. l. The piston ocin the .readyto fire condition of the weapon whereinflthe piston ring 29 will be within the rear end portion-ofthe sleeve 13, which latter portion as more particularly shown in Fig. l is of slightly reduced diameter so as to form an annular ledge 3|. in the plane of the muzzle or forward end. of the piston ring in ready to valve 35' is formed with a ition and the reduced portion'is arrangement disclosed the valve 35 sage leading- 'jointfl shown in Fig.3, 'ger 48 adapted to resiliently engage within any one of a plurality-of recesses-49 formed in the posits tending to collect Within the sleeve 'mirably and that when used chamber 45"with a proper expansion ratio with fire position for a purpose hereinafter made apparent. As well understood in the art the piston is kept in proper alignment within the gas cylinder tube H by bushings interposed in any suitable fiuid sealed manner between the piston and bore of the tube, as for example, the bushing indicated at 32, and communication between the interior of the tube l l and atmosphere rearwardly of the piston ring 29 is established by way of ports 33 so as to obviate the creation of a back pressure within the tube H against which the bushing and piston will have to work and to provide ready escape, for any gases by-passing detachable securing means, such as the self securing cross pin indicated at 34.

The forward end portion of the sleeve i3 is closed by a throttle valve 35 which is formed with a truncated conical surface 36 complementary to the valve seat l1. As shown the longitudinally extending centrally positioned port 31 terminating in an outwardly flared entrance portion 38 adjacent its end of truncation. "The valve 35 is of reduced diameter forwardly of its truncated conical porfixed within the bore in an inturned flange at one end of a valve cage 39, as by meansof' staking indicated at 40.

The inturned flange of the valve cage is provided with a plurality of circumferentially spaced ports 4| outwardly ofthe valve, and the cylindrical portion 42 arranged to surround the valve and the cylindrical portion is internally threaded as indicated at 43 to be interthreaded with the threads 44 formed on the enlarged portion of sleeve l3 forwardly oi the shoulder 14. 1 1n the may be ad justed from seated relation as shown in Fig. l to a'position giving the desired throttled pasfrom the piston clearance or gas chamber 45 defined'by the piston 21, bore I8 of sleeve l3. and valve 35; past the-valve through the ports M in the valve cage 39 to atmosphere. To retain the valve 35in adjusted position relative to sleeve ,l3.there is a spring detent 46 a]?- fixed to the valve cage 39'as by the dove tail whichqhas a detent finshoulder of the sleeve. 1

Although the piston ring29 in the embodiment shown in Fig., 1 is comprised of spaced ring members joinedintegrally by a ring member of smaller outside diameter it will be understood that these elements may be made separately or organized in a different arrangement. It is pref- .erable to fabricate the ring 29 of a material having a hardness greater than that of carbon and which will maintain its red hardness under heat .up to or in excess of 1500 F. so that the ring will serve to broachanycarbon or other fouling del3 whereby. the sleeve may be kept clear of deposits tending .to retard or entirely freeze movement of the piston. I have found that a chromiumcobalt-tungsten alloy steel servesthe purpose adin combination with an aluminum-bronze alloy sleeve l3 having a respect to the displacement of the piston head 28,

will functionwithout entailing the necessity for taking th'efg'as regulator apart for cleaning for periods far superior in point of time than the bearine breads i incline m nnerthat-the do regular periodic cleaning reunited or certain other-parts of the weapon. An, important feature of the invention resides in the establishment or what I term the expansion ratio of the regulator, which is the ratio be,- t wcen the piston clearance 45 with the valve 35 fully seated and the displacement of the piston head. Ihave found by experiment that this ratio must fallwithin a range'between the criticalratios of 4:1 and 1-611, depending upon the stroke of the piston and work required thereof in actuating the mechanism of the weapon, to maintain the requisite volume of gas in the chamber 45 to work upon the piston head, maintain the temperature of the volume sufflcientl'y high toeffect combustion of combustible particles passing from the'barrel to the chamber, be of sufllcient volume toi obtain the elastic characteristics of a fluid medium thereby eliminating shock and hammer sheet, and be such excess volume as to per.- mit the 'passageof gas from the chamber, as by port 37, for the purpose of clearing the chamber of particles that are either not combustible or'have been cleared by thebroaching action of the piston ring 29 after deposition uponthe walls of the chamber and to build up pressure gradually. Ifthe ratio is any less than 4:1 gas entering chamber 45 will strike the piston head 28 a hammer blow, thus delivering a shock to the weapon by reason of the insumcient volume of chamber 45 to permit admission of asumcient volume of gas toabsorb the shock through the elasticity of its own volume and. the necessary rapid build up of operating pressure withsuch small volume, and moreover, the volume or gas will be insufficient in quantity to provide for sumcient expansion to do the necessary work upon the piston head and perform its' scavenging function in removing particles from the chamber through port 31 without falling below the critical pressure requisite to drive the piston. If the ratio is any greater than 16:1 the action becomes lazy due to the large volume to expand, and more important than un der conditions of a smaller ratio so much gas will be-tapped from the barrel as to materially reduce its propelling eifect upon a projectile therein withconsequent reduction of muzzle velocity of the weapon. In practice the expansion ratio for the particm lar weapon is determined in accordance with the stroke of the piston, work to be done by-thepiston, size of the port 3'! in valve and type'of ammunition. The ratio is selected on the basis of the lowest power ammunition to housed with the weaponyand'amount of gas necessary to be ported through the vvalve '35 to thoroughly clear the chamber of all loose "particles while valve 35 is fully closed. With the ratio established on this basis the cyclic rate may be controlled within limits by adjusting valve 35 to pass more or less gas: from the chamber through-the passage between the valve and valve seat 11 and ports 4| to atmosphere, likewise by adjusting valve 35 the same operating conditions may be made to prevail with the use of a higher powered type 01' ammunition as are'obtained with the lowest power ammunition thereby providing for establishment of a uniform cyclic rate of the weapon when fired with any of various-powered ammu nitions designed for use therein.

In operation andwith the barrel I0, gas'cylinder tube ll, bracket l2 and piston 21 assembled as shown in Fig. l the" gas regulator above de-' scribed is assembled as follows: The lock washer lfl-is inserted. upon the end portion of- 'sleeve l3 iormable tabli mey be z-deformed into its coopcrat ng recess Zirwith the alignment symbol .2

rendered visiblei- Thersleeveis then secured to fire ood bor ionts'oi the gas cylinder-t b .H by interthreading its threads 45 withthe threads 16 of the gas cylinder tube and threading the sleeve therein until thes oulder approaches contigu its, with vthe end of tube; H 5 at wh ch time, the tab of washer-.19 bearing symbol zli is deformed into its proper recess- 3.511312 sleeve i3 is then threaded to a pos tion'whereinefiects snug interensa omfin 9f the end o tube"! I washer-l9 and-shoulder M with the alignment symbol 26 n the shoulder in ali nment with the symbol 25 which will effect proper alignment ofthe'ports Hand 24. y'Ifhe remaining-tabs 20 of lockw sher 9- are new deformedinto the recesses '2 lon shoulder 4 thusinterlockinethe sleeve l3 and tube II with ports 23 and 24 aligned and piston head 28 'posi-ticnedin the-sleeve as'shQW .in Fi L', Finally the -ya1v -,cage*38 withv its attached valve 35' is-threaded, onthe forward end of sleeve 13 byinterthreading-the threads 43 thereof with the threads 44.. on sleev 13 until the valve 35 .is in rop r adiustmentlwhich may be d termined by the position of spring d tent 46 elative to the ecess s 49 on shoulder i4, 1 v

The weapcn'hevi zth r u ator asse l d a above described i and otherwise a conditioned for unctio ng wi l.function-as lows with regard to the regulator: Piston 2Y1 occupies the position shown in Fig.1 inthe-ready to fire condition of the weapon. Upon firing a chambered cartridge the gases of explosion will propel the-projectile through the bore of the barrel and when they reach port 23; a portion thereof will enter the port and be admitteditc chamber 45. Since chamber is designed-to constrict expansion in a ratioproportioned to the displacement of piston. head 28 and rate of escape of gas through port '3'! there will be abrupt expansion of gas inthe chamber and than sudden arrestation of expansion to impart an undesirable shock, impact or thrust to the weapon; but rather an expanSiQn that imustyigradually overcome loss of pressure by reason of; escape of gas through port 31, thereby",-necessitatingthat the expansion impart .a gradual accelerating force to the piston wherein its-inertia and load will gradually .be overcome in contrast to-the instantaneous acceleration and accompanying shock obtained when the expansionratio ofthis invention is not provided Aiters the gas has built up a sufiicient pressure in chamber 45 against escape through port 31, the piston 21begins its recoil stroke under radual uni-form acceleration, as the pressure build up is inproper ratio to the piston displacement and gas escape from port 31 to accomplish this predetermined end The piston will travel in recoil performing such work as it is designedto do in theweapon, and be returned in counterrecoil'in any conventional manner to-its-initial po-: sition shown in Fig, 1. Owing to the character of the material of the piston ring 29 it will broach any deposition tending to accumulate on the walls of sleeve I 3 within which it reciprocates and-deposit the broached material'in chamber 45. Likewise the ledge 3 l in the plane of the forward end of the piston inthe-latters normal position of rest will assist in the scavenger action of themeton ring by presenting an edge to the piston ring and 'obstruction to direct-flow of gases between me piston ring and sleeve. Loose particles col lecting' in chamber 45 dlle to the scavenger action 4- of piston ring 29,'or otherwise; wil1 beremoved from the chamber with'the gases flowing through port 31. To regulate the cyclic rate; of the gun within'limits, or for various powered ammunitions, the operator need only adjustthe valve 35-, with respect to its seat 'I"I by r'otatingthe valve cage 39ons1eeve l3. 1

It is to be understood that while the'sleeve I3 is-described as being attached totube II by a threaded connectionthat'such description is'only by way of illustration sinceany suitable means for demountably interlocking these two elements may be employed although the threaded connection is preferred since by the arrang'ement shown the threads are notfsubjected tofreezing by action of deposits made by the gas. l 1

InFig. 4 a modified "form'of' valve 35' which may be used in lieu of valve 35 is' shown. valve has a cylindrical sleeve 50 extending from its truncated end which is adapted to besnugly received within the chamber-45. 'Ports 5| establish communication between the interior of the sleeve and exterior and'a"portfisprovided centrally through the valve"identical "with the-port 31 of valve 35. Valve35' is secured tovalveca'ge 39"in" the same manner as'valve 35. 1 When the valve 35' is used for valvef35 "theregulator is moreeasily cleansed inasmuch as it is only necessary to remove the valve 35"from'slee've l3 and remove carbon or other depositsiof'fouling from the interior ofthe'sleeve SU'instead of from the chamber45. g Y Fig. 5 discloses a m'odifie'd'fo'rm of the regulator applied to the end portion of afgas cylinder tube H having a piston Z'I'therein. plug 52' having an enlarged-outer end 53 is externally threaded and 'r'eceivedih complementally threaded relation within the endof tube H; Theplug j52 1laS'itS rear end portion -longitudinally forwardly bored on inc're ased diameters'to receive the piston head 28 of the piston and form a gas'chambe'r 45. Forwardly ofthe chamber the plug" is formed with a longitudinally extending centrally"'positioned port 54 'compri's'edof the sections 55', 56 and 51*, respectively. Section55'is joined'to' the section 5! of largest diameter by intermediate section 56 of smallest diameter a nd at thez'one of junction of section 56 with section's 55 and5fl the latter sections are properlyflare'd5to' eliminate turbule'nce in the fiow' of gas atom-s ction to "sectio T Section'55 and port ,,58coinbin'eto compel a right angle turn of gas entering chamber 45 from port 58 thereby reducing" climb of the'weaipon". Section 56 iso'f such size as tocon'strict porting from" chamber 45 as to compelafpressure build up in accordance'with the mannerj'de'scribed with regard to the regulator' ofiig fl' and section 51 is sufiiciently largein diameter to eliminat e a back 'pressurebeing builtup therein that would affect porting 'from section 56.

The plug is formed with atransverse opening 59 through its enlarged headfl53 'to receive a locking pin'having resilient legs '50" adaptedto fric tionally secure the pin in the opening and ahead 6| adapted to seat within a recess 62 in the shoulder '53 and end of tube H1 for=interlocking the latter.' In this form of the invention the piston head 28 is formed to have a piston ring 29 consisting of three elements of'largertdiam'eter integrally joined with intermediate elements of smaller diameterand 'asin the case of the form shown inFig. 1 the piston ring 29'is formed of a chromium-cobalt-tungsten steel alloy while the plug 52 is-formed of an aluminumebronzealloy. In

this form' 'of' the invention adjustment is secured by presenting the port58'=of'desired size to the port through tube H leading to the barrel', otherof Fig. 1 has been omitted with corresponding changes in thevalve "35""and s'leevel3? The sleeve [3. which isifof stepped outside diameters is"secu;red"and demountably lookedi-to the tube II as in 'Fig. =1.- =Forwardlyi of'athe portion of smallest outside diameter the sleeve is iormed to receivea spring detent I63. The-valvez35'fl is externally. threaded to be received by i the internal threads 'formed' in the sleeve? l3 and is adjustable to completely-seat the valve so that gas'can escape from ch'amber byway of'port-3'I only, or by .way of ports 5|rpast thevalve. The valve will-be -r'eta'ined" in "positionpf adjustment by detent63-which engages: recessesi in the'sva-lve 351. Thisr modificationwwill function the same as theform of Figwln l r I In the :forms of the invention, illustrated in Figs; 1 to 4.and 6-, the volume ofthetgaschamber is sufficiently large to maintain the-temperature of the gases collected therein highi enough to effect combustion of :combustible particles or similar matter obtaining admission to the chain-- her: which reduces orr=eliminates hash 'of gases ported through-orpast-thevalve. -11 -Havingnow described the -nvention as embodied in. a:present: preferred form I claim:

A 1.. A;gas.regulator:foraniautomatic gun comprising; sleeve having a through cylindric a1 bore adapted'to receive :a pistonfor reciprocable movementiin oneendtportion and being'formed with an axially disposed, conical ,valveseat at itsopposed. endv portion, a piston reciprocably mounted in said one end portionwof the Lsleeve, a valve adapted toreoact withwthe valve'seat to adjust the passage from :thef borew'ipast the va1ve,'-a valve cage for-said valve adjustably mounted'on the sleeve having "a plurality. of. circularly arranged ports open 'to the :atmos'pherep-means securing the valve cage to the sleeve for adjustment to regulate said passageysaidsleevei having a port thereinintermediate the piston and valve adapted to be'placed in communicationwi'th thebore of a barrel.- Yr" x Agas regulator comprisingza sleeve having a through cylindrical 'bore reduced in diameter for a portion-ofits-length adjacent oneend portion to receive al'piston for reciprocable movement in the bore portioniof reduced diameter, the bore of the; sleeve adjacent its end portion opposed to the portion of reduced diameter being outwardly flared to provide a truncated 'conical valve seat, a valve having a. truncated conical surface complemental to said valve seat provided with an axially disposed :portion of reduced; diameter projecting :fromethe basethereofgsaidvalve being formed with an axiallydisposed port, a valve cage having an inturne'dflangeadapted to receive the reducedprojection-of said valve and having aplurality of ports infsaid flangeymeans affixing the reduced. portion-of the valve to'said flange, means fOr adjustably securing the valve cage tethesleeve gwithflthe' valve seatand complementalsurface of the. valve disposed to regulate the passage from the bore, through said ports in the inturned -;flange-ofi the valve Icage, said sleeve being formed witn awport' disposed; intermediate adapted to register with the port in the gas tube the reduced portion of the bore and valve seat for admission of gases.

3. A gas regulator comprising a sleeve having a through cylindrical bore reduced in diameter for a portion of its length adjacent one end portion to receive a piston for reciprocable movement in the bore portion of reduced diameter, the bore of the sleeve adjacent its end portion opposed to the portion of reduced diameter being outwardly flared to provide a truncated conical valve seat, a valve having a truncated conical surface complemental to said valve seat provided with an axially disposed portion of reduced diameter projecting from the base thereof, said valve being formed with a longitudinally extending centrally disposed port terminating in an outwardly flared entrance, a cylindrical valve cage having an inturned flange at one end formed with circumferentially arranged ports, said flange being adapted to receive the portion of reduced diameter of said valve, means affixing the portion of reduced diameter of said valve to said intumed flange with the valve disposed within the cylindrical portion of the valve cage, means for adjustably securing the valve cage to the end portion of the sleeve adjacent said valve seat in substantially fluid sealed relation with the complemental surfaces of the valve and valve seat arranged to coact to regulate passage from the bore of the sleeve through said ports in the inturned flange of the valve cage upon adjustment of the cage, means on said valve cage adapted to coact with a-portion of the sleeve to retain the cage in adjusted position, said sleeve being formed with a port disposed intermediate the reduced portion of the bore and valve seat for admission of gases.

4. The structure of claim 3 wherein said means onthe valve cage for retaining it in adjusted position comprises a spring detent having a free finger secured thereto and the portion of the sleeve with which it coacts comprises an external shoulder thereon intermediate its ends provided with spaced recesses adapted to receive the finger of the detent.

5. The structure of claim 3 wherein said valve also comprises a cylindrical sleeve extending from its truncated end portion fitting snugly within the bore of said first recited sleeve and. having ports formed therethrough adjacent the junction with the valve.

6. In a gas actuated automatic weapon, a gas v regulator including a gas tube cylinder having a gas admission port in its wall, a tubular sleeve vdemountably secured to the muzzle portion of said cylinder and having a gas admission port cylinder, an external shoulder on the sleeve intermediate its ends, means for aligning said ports and interlocking the sleeve and gas tube cylinder comprising recesses in the shoulder and adjacent the end of the gas tube cylinder, a lock washer fitting between the shoulder and said cylinder and having a tab deformable into a recess in the gas tube cylinder, an alignment symbol on the tab rendered visible when the tab is deformed into a recess in the cylinder, an alignment symbol on the shoulder, said symbols being co-related and adapted to be brought into registry to indicate the registration of said ports, and other tabs on the lock washer adapted to be deformed into recesses in the shoulder to further augment the interlocking of the sleeve and gas tube cylinder.

7. The structure of claim 6 wherein the dimensions of said symbol bearing tab and its corresponding recess do not correspond with the other tabs and their corresponding recesses; whereby an operator will always be compelled to deform the symbol bearing tab into its proper recess.

8. A gas regulator comprising a tubular sleeve having its outside diameter stepped from an intermediate zone to one end, a piston mounted for displacement within its bore adjacent the end portion of smallest outside diameter, said sleeve being formed with a forwardly and outwardly truncated conical valve seat adjacent its portion of greatest outside diameter and being interiorly threaded inwardly of the valve seat, a

valve having a truncated conical surface complemental to said valve seat and an integral tubular portion projecting from its truncated end, said valve having ports providing for communication between the interior of the projection and exterior of the valve and disposed in interthreaded relation to the threads in the sleeve with the complemental surface of the valve and valve seat related to coact to regulate the passage from the sleeve through the projection, ports and between said complemental surface of the valve and valve seat to atmosphere upon adjustment of the valve in the sleeve, and said sleeve having a radial gas port therein intermediate the inner end of the projection and the end of the inner stroke of the piston.

9. The structure of claim 8 wherein the portion of the sleeve adapted to receive the piston is of reduced interior diameter from the end thereof to a plane coinciding with the end of the inner stroke of the piston.

10. The structure of claim 1 wherein said valve is provided with an axial port.

SAMUEL' G. GREEN. 

